Warning!!! This post contains information that could be harmful to you or your set. Preforming this modification could void your warranty, result in harm to yourself, damage your TV, burn down your house and cause sterility in small lab rats. DO NOT make these modifications until you understand the risks. DO NOT blame me if you break your set or if your wife accuses you of never closing your eyes anymore when you kiss her lips.
I should start by saying that I am a mild black level junkie. While the black level of this set is really quite good for an LCD, I'm a CRT kind of guy. Anyone who is not a black level junkie will be VERY, VERY happy with this set as-is.
After a week with this display I decided that the black level needed improvement. A full calibration with Avia and SM tweaks were not enough to really tame the black level issue. I think that Panasonic decided to sacrifice black level for a VERY bright display. In its brightest mode this thing has near plasma brightness. This leads to an overly bright bluish gray as the darkest black this set can produce. Contrast is excellent but most scenes have a "fog" over them and dark scenes can be nearly unwatchable for a black level junkie. The user menu and service menu provide no real control over bulb brightness, just the LCD shutters. The LCD panels are incapable of blocking all of the light. The combination of these two factors produces gray blacks.
To control black level I decided to reduce light output. The easiest way to accomplish this is to add a filter to the optical engine. The high intensity discharge lamp in the set does not lend itself to a variable level control(a dimmer). The best filters to use are gelatin filters. These are used to modify image forming beams without introducing aberrations. You should not use stage lighting or theatrical gels. The filter you want is a Kodak Wratten Gel Neutral Density 4x4. The package looks like this:
http://www.perrigoue.com/photo/avs/IMG_2432.JPG
These can be found a pro photo shops and online photo supply houses. They come in many strengths, ranging from 0.10 to 3.00. 0.30 is one stop(50%), 0.60 is two stops (75%). The percentage refers to the amount of light the filter blocks. I bought 1,2 and 3 stop filters to experiment with. After careful evaluation I have decided one stop is about right for me. Black level is significantly improved, scenes are more 3D, dark scenes have improved shadow detail and color. The blue tint in deep shadows is totally gone. Blacks are mostly black, still a tiny bit gray. Bright scenes are still plenty bright and punchy. The set is perfectly viewable in my well lit living room with the sun coming in the skylight and 8x10 glass doors. Two stops is perfect for lights out movie watching, even better than one stop but too dim for daylight viewing. Blacks are truly black without crushing. If you are only using this set for nighttime movie watching I recommend two stops.
In order to preform this mod you will need:
A ND filter
A cardboard filter mount(I used Cokin 84mm X 99mm mounts)
Scissors
Dental Floss
Clear Tape
Latex Gloves
Phillips Head Screwdriver
Be Stupid Enough to not care about your warranty, fire or the whole rat sterility thing.
Step 1: Put on the gloves.
Step 2: Trim the sides of the cardboard mount to allow the image to pass unhindered.(see image below)
Step 3: Mount the filter in the cardboard mount. Use the clear tape to keep it closed, not the built in double sided tape.
Step 4: Poke a hole in the lower left or right corner and thread about 12 inches of dental floss through the hole, tying off one end.
You should now have something that looks like this:
http://www.perrigoue.com/photo/avs/ImG_2427.JPG
Step 5: Unplug the set.
Step 6: Remove the front plastic bezel and remove the projection unit adjustment cover in the center. It should look like this:
http://www.perrigoue.com/photo/avs/ImG_2424.JPG
Look inside the set right above the projection lens assembly(the big round black thing sticking up through the hole). Notice the righteous little "shelf" behind the lens. This is what the back edge of the filter will rest on. Feel inside the opening just above and in front of the lens. You will feel a little shelf sticking out. The front edge will rest on that. The next step is the hardest part:
Step 7: Slide the filter, tail-end-up(the one with the trimmed sides) through the opening in front of the lens assembly. Use both hands. The idea is to get the front edge of the filter onto the little front shelf. Once it's there let the tail end flop over to cover the lens. This sounds way harder than it is. Once you are looking at the set this will make sense.
Step 8: Pull down lightly on the dental floss and use one finger to push up on the front edge of the filter. This will help the filter settle in over the lens. The dental floss also prevents the filter from getting lost in the set if you somehow dropped it. Center the filter over the lens. Here are before and after shots:
http://www.perrigoue.com/photo/avs/ImG_2428.JPG
http://www.perrigoue.com/photo/avs/ImG_2429.JPG
Step 9: Put the cover back on and plug the set back in. Turn it on and look for blocking of the image on the top, bottom and sides. If there is any, turn the set off, unplug it and move the filter in the direction of the blocked edge. Repeat until the image is clear.
Step 10: Put the cover back on leaving the dental floss hanging out(this will prevent the filter from moving in the set) and snap the bezel back in place.
Step 11: Recalibrate and enjoy! I use Cinema mode for lights off HT and Standard mode for daylight viewing. You should calibrate Standard mode during the day with normal room light levels and Cinema at night with the lights off. Standard will have higher Picture and Brightness settings.
Joe
